... I only have two other TPB's on order; Wrath of the Eternal Warrior which shipes this month and Ninjak TP Vol 03 Operation Deadside which hasn't come out yet.
And sadly, I can honestly say, neither are really worth reading.

As much as I am a huge fan of Ninjak, that "Deadside" arc was just not very good. It was also just a little too weird for me. It read like a bad Grant Morrison run

Me reading and going "Ummm, okay ?? But, wait, what?" a heck of a lot and not finding too much joy or fun in it. It may read better collected, I sure hope it does, but monthly ... that run was just too hard to get into.
Also, I have enjoyed some Eternal Warrior at times, but the first 3 issues of that "Wrath of..." run was plenty for me. I stopped after three I think. I may have even opened issue 4 and just stopped at page 2 or something.
As for the rest of your list ...
Eternal Warrior TPB Vol 3 Days of Steel
Harbinger TPB Vol 5 Death of a Renegade
Harbinger TPB Vol 6 Omegas
Imperium TPB Vol 1 Collecting Monsters
Unity TPB Vol 2 Trapped by Webnet
Unity TPB Vol 4 The United
Unity TPB Vol 5 Homefront
Archer & Armstrong TPB Vol 5 Mission Improbable
Archer & Armstrong TPB Vol 6 American Wasteland
Archer & Armstrong TPB Vol 7 The One Percent and Other Tales
X-O Manawar TPB Vol 9 Dead Hand
Dead Drop TPB
Imperium TPB Vol 2 Broken Angels
Unity TPB Vol 6 The War-Monger
Ninjak TPB Vol 2 The Shadow Wars
X-O Manawar TPB Vol 10 Exodus
Book of Death TPB
Book of Death The Fall of the Valiant Universe TPB
Bloodshot Reborn TPB Vol 2 The Hunt
Imperium TPB Vol 3 The Vine Imperative
Ivar, Timewalker TPB Vol 3 Ending History
Unity TPB Vol 7 Revenge of the Armor Hunters
I also think you can stop reading Unity after vol 5 ... maybe 6, but I think vol 5 is the best place to stop. I know vol 7 was just not good as it contains a throw away couple issue arc that wasn't good and a final issue that is like a comedy issue.
I haven't finished the A&A books yet, even though I am piling up the new run now

so I can't speak of how that is. I took a break after issue 5 or so and have yet to find my way back.
Ivar is a great story !!!! But as you only have the 3rd volume listed, I hope you remember what happened. It wraps up well, but you really need to remember what happened prior. Maybe get a refresher before starting vol3?
Imperium had waves of greatness. Just some really good stuff, then it bogged down a tad in the middle but has since regained speed. The robot in there is waay too cool

Bloodshot Reborn is great (still is) and the Ninjak title, except for those issues in vol 3 regarding Nightside

and the Book of Death are pretty fun!!